Four wheel spreading railroad vehicle brake apparatus



United States Patent [72] inventor Robert B.TroyerMenonumeeFaIIs,Wisconsin [21] AppLNo. 699,090 [22] Filed Jan. 19,1968[45] Patented Oct. 20, 1970 [73] Assignee A. 0. Smith CorporationMilwaukee,Wisconsin a corporation of New York [54] FOUR WHEEL SPREADINGRAILROAD VEHICLE BRAKEAPPARATUS 6 Claims, 5 Drawing Figs.

[52] U.S.Cl 188/52,-

188/100,]88/153 [51] lnt.C1 ..B6lh13/00 [50] FieldofSearch 188/52,100(S),153(+) [56] References Cited UNITED STATES PATENTS 2,118,7535/1938 Basett 188/153X 2,181,041 11/1939 Basett 188/52 2,832,440 4/1958Browall 188/52 2,857,184 10/1958 MancusiJr 188/100SUX 3,088,550 5/1963Kirk 188/52 47 l 2;- s T l 1 3,177,984 4/1965 Taylor 3,335,825 8/1967Mersereauetal.

Primary Examiner-George E. A. Halvosa Attorney- Andrus. Sceales, Starkeand Sawall ABSTRACT: A railroad friction-braking system utilizes arelatively high power air piston cylinder of the Teflon seal type, inconjunction with a linkage assembly. The apparatus is used to move theusual set of parallel brake beams to engage connected brake shoes witheach wheel in the wheel truck. The air cylinder mounted within the truckbolster is slightly off center and has a piston and rod adapted formovement in a horizontal plane sideways of the truck. The rod isinterconnected to a crosslever secured to a fixed pivot on the bolster.A rigid link connects the center of the crosslever to a live brake leverwhich is pivotally connected to the brake beam on the opposite side ofthe bolster. Further, a rigid link interconnects the middle of the livelever to the middle of the dead lever which is pivotally attached to theother brake beam. The dead lever is connected at its top end to a deadlever fulcrum. Operation of the air cylinder pivots the live lever andcauses the first set of brake shoes to engage their correspondingwheels. The live lever then pivots about the engaged Wheels to cause thedead lever to pivot thus engaging the second set of brake shoes withtheir wheels.

Patented Oct. 20, 1970 Sheet II I! FOUR WHEEL SPREADING RAILROAD VEHICLEBRAKE APPARATUS This invention relates to a railroad vehicle brakeapparatus and particularly to the air actuated brake apparatus having anair cylinder and linkage assembly for applying of the brake means to thewheels.

Railroad vehicles or cars have generally included two axle four wheeltrucks at the opposite ends. Each of the trucks includes a crossbeam orbolster to which the wheels are secured and a pair of parallel extendingbrake beams disposed between the sets of wheels and moved in oppositedirections to engage suitable brake shoes with the respective sets ofwheels. Various systems for operating or moving of the brake beams havebeen suggested.

The brake beam may be connected by a linkage to an air activatedcylinder-piston motor means for applying the brake shoe against thewheel and providing friction stopping of the railroad car. The requiredoutput force of the cylinder-piston motor means can be very substantialparticularly where the railroad car is of a relatively heavyconstruction. Consequently. special constructions of the cylinder arerequired, particularly to maintain a sliding seal of the piston withinthe cylinder.

The present invention is particularly directed to a reliable andinexpensive brake apparatus for establishing the necessary braking forceon the brake beams of a railroad vehicle.

Generally in accordance with the present invention, the air powercylinder means is mounted directly inside of the bolster of the railroadtruck with a piston mounted for sliding movement in a horizontal plane.The shaft or rod extends horizontally outwardly through one of the wallsof the bolster and is interconnected to a linkage to provide sequentialapplication of the forces to the brake beams. The cylinder is mountedonly slightly off center of the railroad bolster and brake beams toprovide a near-central positioning of the operating shaft or rod. Afirst or live brake lever has its lower end connected to the brake beamand the upper end connected by a connecting pull link to a crossleverwhich is connected respectively to the bolster and to the outer end ofthe piston rod. A second or dead brake lever adjacent the output shaftof the cylinder has its lower end connected to the other brake beam andthe upper end to a dead lever fulcrum. A push link connects the centralportion of the brake levers. Air is supplied to the power cylinder andthe related rod moves outwardly pivoting the cross lever outwardly. Thisexerts a pulling force on the connecting link which is transmitted tothe lever and brake beam on the opposite side of the bolster. The pullforce pivots the lever and moves the brake beam such that the shoesengage the wheels. The wheels act as a pivot point such that furthermovement of the lever in addition to exerting a braking forceestablishes a pushing force on the connecting rod and a related pivotforce to the lever connected to the dead lever fulcrum and therebycauses the opposite beam to also move into engagement with the wheel.

This construction has been found to provide near central forceapplication and more important has been found to minimize the verticalloading of the cylinder rod and wear on the linkage. The significance ofthis is that applicant has found that it can now employ a highlyimproved cylinder construction wherein the piston is sealed to the wallof the cylinder with a spring loaded plastic seal such as "Teflon typeseal. This provides exceptionally long operating life.

Referring to the drawings:

FIG. 1 is a plan view of a railroad car truck with parts broken away tomore clearly disclose the construction of the present invention;

FIG. 2 is an enlarged vertical section through the power cylinder shownin FIG. 1;

FIG. 3 is an enlarged fragmentary view of FIG. 2 more clearly showing aseal structure;

FIG. 4 is a front elevational view of the linkage structure shown in H6.1; 9

FIG. 5 is a fragmentary view taken generally on line 5-5 of FIG. 4.

Referring to the drawings and particularly to FIG. a two axle four wheelrailroad car truck assembly is shown having pairs of wheels 1 and 2mounted to the opposite sides of the truck assembly and interconnectedto the opposite ends of each of two axles, not shown. The axles areinterconnected to side frame member 3 of a centrally located truckbolster 4 in accordance with any well known or desired construction. Apair of brake beams 5 and 6 are also disposed one each to the oppositeside of the truck bolster 4. Each of the brake beams 5 and 6 extendscrosswise of the car truck in parallel spaced relation to each other andto the truck bolster d. The outer ends of brake beams 5 and 6 aresimilarly constructed and slidably mounted on the side frame members 3as diagrammatically shown by a sliding tab and groove support 7.

Each brake beam is generally an isosceles triangular-shaped frameworkwhich may be formed as a cast iron or a fabricated steel member. Thebase of the beam is adjacent the bolster and the apex is disposedoutwardly generally centrally between the wheels. A brake head 8 issecured to each outer end of the brake beams in alignment with theassociated wheels I and 2. Brake shoes 9 are releasably interconnectedto the brake head 8 and are of the composition type. The brake beams 5and 6 are positioned to provide frictional force engagement of the brakeshoes 9 with the associated wheel through the operation of a powercylinder unit or assembly it) which is mounted within the bolster 4 inaccordance with the present invention. The power cylinder assembly It)includes an output shaft or rod ll interconnected to a linkage 12 forsequentially actuating the brake beams 5 and 6.

More particularly, the bolster 4 is an inverted box-shaped channelmember. The power cylinder unit lib includes a cylinder or casing 13disposed within the bolster with a horizontal axis extending in thedirection of movement of the truck assembly. The housing 13 fits withina suitable chamber defined in the bolster 4 by the back wall 14- and aplurality of lateral brace walls 15 which are integrally formed with thebolster. The forward wall 16 of the bolster includes an opening forinsertion and removal of unit 10. In the assembled relation, the frontcylinder wall 17 is aligned with the front wall 16 of the bolster. Aplurality of clamping bolts 118 are interconnected to the front wall 16of the bolster and secure clamping washers 19 in overlapping andclamping engagement to the outer peripheral edge of the front wall 17 toreleasably lock the housing 13 within the chamber. The back wall 20 ofthe cylinder housing 13 includes a pair of antirotation guide pins 21which extend through corresponding support openings 22 in the back wall14 of the bolster to properly locate the power cylinder unit 10 in thebolster. An air entrance fitting 23 is secured to the back wall or head20 of the cylinder housing l3 and projects through an opening in theback wall 14 of the bolster for connection to a suitable air hose.

The cylinder structure itself is most clearly shown in FIG. 2. Acup-shaped piston 24 is slidably mounted within the housing 13 with theouter face of the piston continuously urged toward the back wall or head20 which thus constitutes the head of the cylinder. A bias spring 25acts between the piston 24 and forward wall 17 to continuously urge thepiston 24 toward the head 20.

The head 17 is removably secured within the cylinder 13 by a retainingring 26 with the spring 25 urging the head 17 outwardly into clampingengagement with the ring. A filter opening 27 is provided in theremovable head 17 to permit ready breathing with respect to the backsideof the piston 24. A hearing 28 is secured centrally of the wall 17 toslidably support the piston rod or shaft 11 which extends into thehousing and is welded or otherwise secured to the central portion of thepiston 24.

In accordance with the present invention the outer corner of the piston24l is recessed as at 29 to receive a generally U- shaped plastic sealmember 30, most clearly shown in FIGS. 2 and 3. The seal member 30 opensoutwardly towards the head 20. A suitable ring spring member 31 assistsin holding the outer lip in sealing engagement with the inner face ofthe cylinder. The seal is formed of any suitable self-lubricating typeplastic such as that widely sold under the trademark Teflon". A Teflonseal is extremely desirable in that it will operate properly withminimum friction drag while under wide temperature variations such asencountered in railroad car usage. The inner face of the cylinder ispreferably chrome plated to present a smooth highly finished surface tothe sealing lip of the plastic seal member 30. The U-shapedconfiguration results in the application of a sealing force to the seallip when air power is applied via the air tap 23.

A wear ring 32 is provided on the skirt portion of piston 24.

Although this type of seal has been employed in other applications,normally the wear and loading characteristics of the conventionalrailroad car truck are such that this form of seal has not beenconsidered satisfactory for the power cylinder arrangement in a railroadcar. Applicant has found however that the linkage structure as shown andpresently described permits use of a similar sealing arrangement for arailroad car truck.

The rod or shaft 11 is generally a tubular member to which a shaft plate33 is welded or otherwise secured as at 34. The outer end of the shaftplate is provided with a slot 35 having rounded ends. Slot 35 is adaptedto receive a disc end 36 of a cross lever 37 forming a part of theinterconnecting linkage 12, as most clearly shown in FIGS. 1 and 2.

The cross lever 37 is generally a platelike member having the one endformed in the disc configuration of a diameter somewhat less than thewidth of the slot 35. The lever is mounted with the disc-shaped end inthe slot and as most clearly shown in FIG. 4 extending laterally acrossthe bolster and upwardly with the opposite end pivotally connectedwithin a bifurcated pivot bracket 38 which is bolted to the bolster asat 39 to properly locate the bracket generally in the plane of thecrosslever. A pin and cotter key unit 40 firmly fixes the end of thecrosslever 37 to the pivot bracket 38.

The power cylinder unit as most clearly shown in FIG. 4 is disposed tothe one lateral side of the center of the bolster 4 and in a generallycentral vertical position.

A pull rod 41 is interconnected to the intermediate portion of thecrosslever 37 by a bifurcated pivot pin connector 42 and extends throughthe bolster 4. The connection of the pull rod 41 is generally to theside of the bolster adjacent cylinder unit 10 and thus to the left ofcenter as viewed in FIG. 4. It extends rearwardly generally in ahorizontal plane with the opposite end interconnected to a live brakelever 43 by a bifurcated connector 44 which is threaded into theadjacent end of the link 41. The live brake lever 43 is generally aplatelike member with the lower end pivotally interconnected by asuitable pivot pin unit 45 between a plurality of longitudinallyextending crossbeam braces 46 forming a part of the brake beam 5. Thelongitudinal braces 46 are disposed at an angle to the horizontal andvertical plane to mount the live lever 43 extending upwardly andlaterally of the bolster and generally at a perpendicular to that of theplane of crosslever 37. This locates the longitudinal braces 46centrally of the brake beam 5 with the interconnection to the crosslever42 to the one side thereof. However, the forces transmitted are such asto provide longitudinal movement of the brake beam 5 without undesirabletwisting thereof.

A connecting push rod 47 includes an integral bifurcated end which isinterconnected to the live lever 43 intermediate the connection of thelongitudinal braces 46 to the pull rod 41 by a suitable pin 48. Theconnecting rod 47 extends back through the bolster 4 with the oppositeend similarly pinned to a dead lever 49 for brake beam 6 by a pin 50.

The dead lever 49 is generally similar to the live lever 43 and isinterconnected at the lower end in a similar manner to the longitudinalbraces 51 of the brake beam 6 by a pin 52. The upper or outer end of thelever 49 is pivotally secured by a pin 53 to a dead lever fulcrum 54, asshown most clearly in FIGS. 1 and 5, with the upper end of the leverlocated outwurdly of the pin 52. Generally the fulcrum 54 is a U-shapedmember with the ends pivotally attached to a bracket 55 which is securedto the front wall of the bolster. The dead lever extends between thewalls of the fulcrum and is secured therein by a suitable pin 53.

The brake beams 5 and 6 are normally positioned in slightly spacedrelation to the wheel 2 as a result of the positioning of the powercylinder piston 24 adjacent the head 20, as shown in FIG. 2, under theaction of the bias spring 25. When the brakes are to be applied, airunder pressure is applied to the power cylinder unit 10 and particularlybetween the piston 24 and the head 20. It is well known that very highpressures can be established between the piston and cylinder with thestructure of seal 30, as shown in FIGS. 2 and 3. Consequently very highbraking forces can be established. The high pressure is transmitted bythe outward movement of the piston and piston rod 11 to the crosslever37 which pivots outwardly, in a counterclockwise direction as viewed inFIG. I. The pivotal movement of the crosslever 37 exerts a pull on thepull rod 41 which is transmitted to the live lever 43 resulting in apivotal movement thereof about the pin connection 48. The generallyperpendicular mounting of the crosslever 37 and the live lever 43permits the pivotal movement of the levers without undue lateral loadingof the linkage and the piston 24. The lower end of the lever 43 which isconnected to the center of brake beam 5 pivots in a counterclockwisedirection in FIG. 1 causing the brake beam to move outwardly and movingthe shoes 9 into braking engagement with the wheels 2. When the shoes 9engage the wheels and provide a braking force, they simultaneouslyconstitute a new pivot point for the live lever 43 resulting in pivotalmovement of the lever 43 about the brake beam pivot connecting pin 45.This results in a push on the connecting link 47 which in turn resultsin a corresponding force on the dead lever 49. The lower end of the deadlever 49 can only move in a straight line and the dead lever 49 pivotsin a counterclockwise direction about the fulcrum pin 53 to move thebrake beam 6 toward the wheels and causing the brake shoes 9 to engagethe wheels 2. The fulcrum pin 53 is located outwardly of pin 52 and thepivoting of lever 49 also exerts a cross force in the plane of the lever49. The fulcrum 54 is pivoted to bracket 55 and thus pivots upwardly asshown in phantom in FIG. 5 to accommodate this movement.

Applicant has found that the mounting of the cylinder unit 10 within thebolster provides a protective shield for the cylinder and minimizes theshock forces applied thereto contrasted to the usual direct mounting ofthe cylinder on a side frame member or the brake beam. The location ofthe cylinder unit 10 within near center of the bolster and the angularlyrelated levers and linkage establishing central location of theconnection to the brake beams 5 and 6 substantially minimizes thevertical loading on the cylinder unit and linkage system 12 and thuspermits the use of a small compact power cylinder unit with aplastic-type seal.

I claim:

1. A railroad vehicle braking apparatus having first and second brakebeams and a bolster, a fluid power cylinder unit mounted within saidbolster and having a horizontal shaft, said fluid cylinder unitincluding a head including a fiuid source connector and a piston securedto said shaft and having a sealing member disposed between the pistonand the cylinder wall, and a linkage interconnecting said shaft to saidbrake beams and including a pair of brake levers connected one each tosaid beams and interconnected by a first connecting rigid link extendingthrough said bolster, a first fixed pivot support secured to the bolsterin laterally and vertically spaced relation to said shaft, and acrosslever disposed between said brake levers and connected at one endto said shaft and extending laterally and vertically therefrom acrossthe bolster to said first fixed pivot support, and a second rigid linkconstituting a pull member extending longitudinally from the one side ofthe bolster through said bolster to the opposite side and connectingsaid cross lever to the first brake lever on the opposite side of thebolster, a second pivot support connected to the second brake lever onthe same side of the bolster as the crosslever to pivotally support thecorresponding brake lever, said levers being located and arranged tominimize lateral loading of the connections and thereby vertical loadingof the cylinder unit.

7 2. The brake actuating apparatus of claim 1 wherein said pistonincludes an encircling corner recess, a self-lubricating plastic sealmember disposed within the recess and having a sealing lip engaging aninner wall of the cylinder unit and projecting toward said head,

' 3. The brake actuating apparatus of claim 1 wherein said pistonincludes an encircling corner recess, a self-lubricating plastic sealmember disposed within the recess and having a sealing lip engaging aninner wall of the cylinder unit and projecting toward said head, theinner wall of said cylinder being finished to present a smooth slidingsealing surface to said lip.

4. The railroad vehicle braking apparatus of claim 1 wherein:

said fluid power cylinder unit is mounted to one side of center of saidbolster and immediately above the plane of the brake beam;

said crosslever is pivotally connected to said shaft and extendslaterally and upwardly from said shaft to said first fixed pivot supporton the face of said bolster, said second rigid link being connected tothe central portion of said crosslever and extending substantiallyhorizontally through said bolster to said one side of center andconnected to the outer end of the first brake lever, said brake leversbeing coplanar and extending upwardly and laterally from the relatedbrake beams, said first link being connected to said first brake leverbetween the connections to the second rigid link and to the first brakebeam and extending through said bolster, to said one side of center, andsaid second pivot support including a fulcrum pivotally connected tosaid bolster and to the upper end of the second brake lever outwardly ofthe connection to the second brake beam to actuate the second brakebeam.

5. The railroad vehicle braking apparatus of claim 1 wherein, pullmember extends substantially horizontally through said bolster, saidfirst brake lever being connected to the outer end of the pull memberand the first brake beam, said first rigid link being a push memberconnected to said first brake lever between the connections to the pullmember and to the first brake beam and extending through said bolster,said second brake lever pivotally connected to the second brake beam andto the bolster and said push member being pivotally connected to anintermediate portion of the second of said brake levers to actuate thesecond brake beam.

6. The railroad vehicle braking apparatus of claim 1 wherein,

said crosslever includes a disc end mating with a slot in the outer endof said shaft and extends laterally and upwardly therefrom, said firstfixed pivot support including a pivot axis generally perpendicular tothe principal plane of said disc end, said pull member pivotallyconnected to said crosslever with a pivot axis perpendicular to theplane of said disc end and extending substantially horizontally throughsaid bolster, and pivotally connected to the first brake lever to theopposite side of the bolster, said last named brake lever being a livelever connected to the adjacent brake beam and extending upwardly at anangle normal to the crosslever, said first rigid link being a pushmember connected to said live brake lever between the connections to thepull member and to the first brake beam and extending through saidbolster, said second brake lever being a dead lever pivotally connectedto the second brake beam and extending upwardly in the same plane assaid live lever, said second pivot support including a fulcrum pivotallyconnected to the bolster, and a pivot connection between the fulcrum andupper end of the dead lever located outwardly of the pivot connection ofthe dead lever to second brake beam to actuate the second brake beam.

